October 30, 2006

Two new reviews of Brizendine

Two very skeptical reviews of Louann Brizendine's The Female Brain have recently appeared, both under cleverly impolite headlines.

Rebecca M. Young and Evan Balaban (or the editors of Nature) make a pun on "psychoneuroendocrinology", titling their review "Psychoneuroindoctrinology" (Nature 443(7112), p. 634, October 2006). Young and Balaban are brutally critical: they say that the book "fails to meet even the most basic standards of scientific accuracy and balance", "is riddled with scientific errors", and "is misleading about the processes of brain development, the neuroendocrine system, and the nature of sex differences in general". Perhaps their most important single point is this:

Human sex differences are elevated almost to the point of creating different species, yet virtually all differences in brain structure, and most differences in behaviour, are characterized by small average differences and a great deal of male–female overlap at the individual level.

I've made free to put a copy of this review on the Language Log server, since I believe that a much broader audience will be interested in this topic than those who can justify the $199/year that I pay to subscribe.

Liz Lopatto's review in Seed Magazine has been given an even more startlingly impolite headline: "The Female Brain Fart". Lopatto went beyond checking Brizendine's references: she called up some of the cited authors, who said things like "My data don't speak at all to whether or not girls are compelled from an early age to attend to faces" (Erin McClure), and ""There is nothing in my study that seems to warrant this reference" (Ron Stoop).

Lopatto also links to a list of sexual biology posts on Language Log ("David Brooks, Neuroendocrinologist"), and then creates a sort of virtual debate between Dr. Brizendine and me:

Brizendine said, via email, that she inserted citations in order to "provide a resource for those young researchers and students who wanted to go deeper into the field of gender-specific biology," rather than to assert something conclusive.

But Liberman suggests these references actually serve to present her as an authoritative voice. While scientists publishing the results of their research in journals are held to rigorous standards of peer-review, the standards for popular science books are much more lax, Liberman said. He said he finds it disturbing that Brizendine chose to invoke the scholarly form of using citations.

"Brizendine and other authors like Leonard Sax,"—a physician and author of the 2005 book Why Gender Matters—"are interesting in that they have quite an elaborate scholarly apparatus: They have endnotes and extensive bibliographies," he said. "There's a substantial amount of credibility from credentials and employment, and the long list of references and footnotes present a certain impression about the solidity of the assertions that are made: This is not just an opinion and not just the opinion of an expert, but the backed-up opinion of an expert."

To avoid a possible misunderstanding, let me explain that I don't "find it disturbing that Brizendine chose to invoke the scholarly form of using citations". I think it's a Good Thing for works of popular science to cite their sources. What bothered me was the fact that she -- like Leonard Sax and some other writers on this topic -- cites sources that are irrelevant or even contrary to the specific (controversial or false) assertions in the text.

[By the way, I may be too old-fashioned, but I thought that Seed's headline was inappropriate. This is partly because the scatology seems like a cheap shot, but also because none of the meanings of the term "brain fart" really seems to fit this case. Sources on the internet offer glosses such as "A lapse in the thought process; an inability to think or remember something clearly" (Wiktionary); "The actual result of a braino, as opposed to the mental glitch that is the braino itself. E.g., typing dir on a Unix box after a session with DOS" (Jargon File); "An inelegant way of saying, 'I forgot,' it refers to your mind going blank. Someone may say, 'Sorry, I just had a brain fart.' It can also refer to a situation in which someone speaks 'out of turn,' especially to a superior. For example, if you march into your boss's office and speak your mind without first thinking about the possible consequences, you've just had a brain fart." (NetLingo); "Quick-and-dirty creative output. The byproduct of a mind stuffed with food for thought that can therefore produce information without effort." (WordSpy). Only the last of those has any plausible connection with Brizendine's book -- its problems appear not to be due to forgetfulness or lapses in thought, but rather to the elevation of ideology over science, and to something between sloppiness and misrepresentation in the use of references.]

I'll close with the ending of the Young and Balaban review, which expresses the culture-wars aspect of this issue clearly:

Like other popular books on the biology of human nature, The Female Brain has a rigid plot line: the foil of 'political correctness' against which the author wages a struggle for truth. We are told that the media, feminists, pointy-headed intellectuals and a vaguely specified 'culture' dogmatically insist that gender or racial differences in personality and behaviour are entirely cultural, an observation that is hard to reconcile with the volume and tone of media attention to the biology of gender and sexuality. [...]

Ultimately, this book, like others in its genre, is a melodrama. Common beliefs are recast as imperilled and then saved. Stark, predictable protagonists (an initial "cast of neuro-hormone characters" that reads like a guide to astrological signs) interact linearly with foreseeable results. The melodrama obscures how biology matters; neither hormones nor brains are pink or blue. Our attempts to understand the biology of human behaviour cannot move forward until we try to explain things as they are, not as we would like them to be.

That melodramatic plot line is sometimes a true picture of the situation -- certainly there are plenty of people who deny any human sex differences in cognition as a matter of ideological commitment rather than empirical fact -- and so perhaps there is a bit of truth in this aspect of the story told by Brizendine, Sax and others. The clearest example of such a melodrama that I know about was Paul Ekman's struggle, against the likes of Margaret Mead, Gregory Bateson and Ray Birdwhistell, to establish that human facial expressions are not socially constructed. But that's a topic for another post.